“Helping to turn my family’s business into a global company has been a big part of my life,” she said. “Now I’d like to help make our great state of Wisconsin even better.”

Democrats think Walker’s Achilles’ heel is jobs. When he ran in 2010, he promised to create 250,000 private-sector jobs by the end of his first term. He’s less than half way there and will ultimately fall short of the goal, but he’s maintained an approval rating around 50 percent.

Burke notes in her video that Wisconsin ranks 45th of the 50 states in projected job growth, according to Moody’s, trailing Midwestern neighbors like Minnesota and Ohio.

“I’m running for governor because we can do better than that, a lot better,” she said, without mentioning Walker by name. “Just like Washington, our state capitol has become so focused on politics and winning the next political fight, it’s pulling our state apart and our economy down.”

Walker’s campaign responded to her video by touting the governor’s success on other metrics.

“Under Governor Walker’s leadership, Wisconsin has balanced a $3.6 billion deficit, cut income taxes, and we’ve seen our best two-year job growth in a decade under any governor,” spokesman Jonathan Wetzel said in an email.

The open question is how many millions of her own money Burke will pour into making this race competitive.

Walker has become a fundraising powerhouse, and the left is somewhat fatigued after labor unions lost their effort last year to recall Walker for reforming collective bargaining.

Republicans believe Burke is not ready for prime time, noting that the first elected office she sought was a school board seat in the state capital of Madison last year. She spent $128,000 to prevail in the state’s most liberal enclave. Burke does not mention her post on the Madison school board in the announcement video.

Undoubtedly, Walker would have entered 2014 as one of the top targets of national Democrats had the recall not strengthened his political standing and made him a conservative folk hero. Now he will be very tough to beat.

His challenge is to win reelection in a state President Barack Obama carried last year by 7 points, even with Wisconsinite Paul Ryan as Mitt Romney’s running mate, without moderating his very conservative governing record and while still building up a profile in the early states.

Top Democrats in Wisconsin acknowledge that Walker is the front-runner, but they believe they have a duty to the national party to bloody the governor as much as possible and to deny him a coronation.

Because the state is so polarized, Walker’s team does not believe he could realistically win by more than a few points even in the best-case scenario. They kept the political operation intact after the recall in anticipation of 2014.

Burke touts her time as secretary of commerce in the cabinet of former Gov. Jim Doyle. She says the state had 84,000 more jobs when she was in office than today, with a 4.8 percent unemployment rate.

Republicans see her ties to Doyle, who left office with low approval ratings, as a major liability. They plan to argue that Walker has spent the past few years cleaning up a mess that Burke helped create. The state Republican Party reserved the domain name maryburke.com and has already filled the page with attacks on her record.

Republican Governors Association Executive Director Phil Cox called Burke a “sacrificial lamb,” noting that Democrats settled on her only after several higher-profile recruits, such as former Sen. Russ Feingold and Rep. Ron Kind, took a pass.

“His record says it all: Gov. Walker is moving Wisconsin forward,” said Cox.